1. Field of the Invention
This invention relates generally to lapidary machines, and particularly to semi-automatic machines which can be used to efficiently and accurately cut the profile of a gemstone that has been sliced and roughly cut to the desired profile. 2. Description of the Prior Art
Conventional lapidary machines while well suited for their primary purpose of profiling gemstones, are generally not suited for mass production operations. Accordingly, a substantial amount of labor is required to change dopsticks in the chuck of the machine. Not only is a great deal of time consumed in operating the conventional drill-type chuck commonly employed with lapidary machines, but even more time is lost by the need to visually align the dopstick and stone with the stone guide of the machine. Further, the usual work holders effectively prevent a dopstick supporting a stone finished on one lapidary machine to be transferred to another lapidary machine in order to dome the top of the stone.
Another problem commonly encountered with conventional lapidary machines is that the grinding wheel and stone are occasionally damaged by rapid movement of the chuck holding the dopstick supporting the stone relative to a grinding wheel of the machine such that the stone strikes the wheel.
U.S. Pat. No. 3,673,742, issued July 4, 1972 to S. A. Colbaugh, discloses a lapidary machine particularly adapted for producing cabochon shaped gemstones and including a swinging chuck arrangement which cooperates with a slide-mounted guide wheel and an annular grinding surface disposed perpendicularly to the extent of the stone carrying dopstick and associated chuck. Further, U.S. Pat. No. 1,998,642, issued Apr. 23, 1935 to E. C. Smith discloses a stone shaping device with a slidably mounted, manually orientable dopstick holder, while U.S. Pat. No. 3,568,369, issued Mar. 9, 1971 to E. G. Marshall, discloses another example of a gem grinding machine wherein the work holder swings toward and away from the grinding wheel of the device.